Belgian drilling company BEMCO S.A. is in the midst of completing the installation of catenary foundations to provide new overhead electric power to the world-famous TGV trains that run throughout Europe. This is the second such project on TGV rail lines BEMCO completed, utilizing Numa downhole hammers and bits to efficiently drill the required holes.
This project is on the Marseille Line of TGV, and requires the installation of foundation holes in hard limestone and overburden ground formations. To conquer these tough conditions, BEMCO is utilizing Numa’s Champion 180 and Challenger 125 downhole hammers to drill 24-inch and 22-inch holes to a depth of 7 feet. The firm selected the Numa hammers based upon its past experience with them. Crew members were impressed with the performance of Numa’s Challenger 125 on the first part of the drilling project, so they added the Champion 180 to provide for additional hole-size flexibility and more power.
All the drilling for the electrification project has been conducted by a drill mast and rotary unit manufactured by Stenuick France, which is mounted on a backhoe arm. This backhoe drill rig enables easy access to confined and difficult-to-reach drill sites along the tracks. It also eliminates the need for a train-mounted rig that could congest busy rail lines and slow rail traffic. Once at a drill location, the backhoe arm positions the hammer over the designated hole location, and then drills the required 7 foot depth. Two 750-by-150 air compressors were used to power the Challenger 125 for the 22-inch holes, while two 900-by-150 compressors were used for the Champion 180.
As with all Numa DTH hammers, the Champion 180 and Challenger 125 have heavier pistons than most traditional hammers, which can provide more impact power, resulting in faster penetration rates and longer life. During the second stage of the TGV electrification project, the Champion 180 and Challenger 125 hammers have been running continuously without the incidence of downtime. This type of hammer performance has allowed BEMCO to continue to achieve tremendous drilling success, just as it did on the first portion of the project.